1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to digital television (DTV), and more particularly, to execution of a DTV application program.
2. Description of the Related Art
A DTV is a TV capable of receiving digital signals rather than analog signals. In its broadest meaning, DTV may be understood as not only a broadcast system that provides services using digital frequency bands, but also various additional services. Since broadcast content is manufactured using digital equipment, the rate of restoring the broadcast content is better when the content is transmitted using digital signals than when the broadcast content is received using analog signals. Therefore, it is possible to provide high-quality images, sound, and additional data services.
A DTV receives digital broadcast signals obtained by multiplexing an audio/video broadcast signal, channel information, program schedule information, an application program, and data such as images and class files, which are required by the application program.
In this case, the application program can be executed in the DTV and is also referred to as an “Xlet”. Representative examples of an Xlet application program include news, traffic information, weather information, stock information, games, and so on. If bi-directional communication can be established, the Xlet may provide various shopping mall transactions, bank services, or stock exchanges (which are commonly referred to as “T-commerce”), as well as on-line game services, messenger services, electronic mail services, etc. However, a large part of application programs, and images and class files requested by each application program are transmitted using a carousel method.
The term “carousel” literally means continuously repeating in a circular course. Since data such as a file is delivered in a single direction, the same data must be repeatedly transmitted for reliable transmission. Therefore, in general, the carousel method is used to transmit a file. The carousel method may be performed in the same way that a disc is used. However, since data is repeatedly transmitted according to the carousel method, if a desired file is not downloaded to a cache of a memory of a DTV, an application program must wait for the file to be transmitted in order to read it, thus causing high latency.